Thanks a lot ehroof.

The world just got better with helpful forums.

I tried a remedy on the center drive shaft.
Drilled a 1.5mm hole perpendicular to the original pin hole and about 2 mm away from it (as far as I could go).
Then inserted a home made 1.5mm shaft and secured it.

I did this on both ends, so now each end of my center drive shaft is locked with 2 pins.
A test run was done, about 30 mins, mostly top speed runs with sudden brakes and wheelies and violent spins and 'brakies' and some small jumps.

So far so good. I sure hope it will hold for a long time. It's just ashame it didn't come with a slipper clutch.

Oh yes, I must admit. I am NOT having a Redcat Volcano EPX. There's simply no Redcats in our local market.
However my model is HSP (High Speed) Brontosaurus, I think they are the same.